Optimized cushioning elements

ABSTRACT

A cushioning element includes a plurality of interconnected walls that define hollow columns. The interconnected walls include voids. The voids have shapes, sizes, and positions that reduce an overall density and weight of the cushioning element without sacrificing its cushioning characteristics. The cushioning element may even be thinner than an existing, conventionally configured cushioning element while providing the same or improved cushioning. In some embodiments, the cushioning element may also include enlarged junctions between interconnected walls or other stiffening features. Methods for designing such cushioning elements are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

A claim for priority to the Jul. 25, 2023 filing date of U.S. Provisional Patent Application No. 63/391,995, titled OPTIMIZED CUSHIONING ELEMENTS (“the '995 Provisional Application”), is hereby made pursuant to 35 U.S.C. § 119(e). The entire disclosure of the '995 Provisional Application is hereby incorporated herein.

TECHNICAL FIELD

This disclosure relates generally to cushioning elements in which a plurality walls are interconnected to define hollow columns and, more specifically, to techniques for maintaining the cushioning characteristics of such cushioning elements while optimizing (e.g., reducing, etc.) their thicknesses, weights, and/or densities. Even more specifically, a cushioning element that includes a plurality of interconnected walls defining a plurality of hollow columns may include one or more stiffening features and/or one or more voids in the walls that define the hollow columns. Methods for designing a cushioning element with interconnected walls that define hollow columns to optimize (e.g., minimize, etc.) the thickness, weight, and/or density of such a cushioning element are also disclosed.

SUMMARY

A cushioning element of this disclosure includes a plurality of interconnected walls that define a plurality of hollow columns. Walls of the plurality of interconnected walls may be formed from an elastomeric material. The walls may be arranged in such a way as to define a grid (e.g., a square grid, a rectangular grid, a triangular grid, a hexagonal grid, etc.), with the hollow columns comprising the spaces defined by the grid. The hollow columns may be arranged in an array. The walls and/or hollow columns of such a cushioning element may include features that enable the cushioning element to have predetermined cushioning characteristics and, thus, to cushion an object (e.g., an individual, etc.) in a predetermined manner while optimizing (e.g., minimizing, etc.) one or more of a thickness, weight, and density of the cushioning element. In this regard, the walls and/or hollow columns of a cushioning element according to this disclosure may have configurations (e.g., stiffening features, voids in the walls that define the hollow columns, etc.) that impart the cushioning element with a predetermined stiffness and/or weight.

The elastomeric material that forms the plurality of interconnected walls may comprise any suitable material that will readily deform when placed under a load and resiliently rebound upon removal of the load. In various embodiments, the elastomeric material may comprise a gel. In a specific, but non-limiting example, the gel may comprise a block copolymer that has been extended with a plasticizer. A non-limiting example of a block copolymer is a triblock copolymer, such as a so-called A-B-A triblock copolymer. A non-limiting example of a plasticizer is mineral oil. Other so-called “synthetic rubber” materials and other materials that may be used to form the walls include, without limitation, rubber, foams (e.g., polyurethane foams, etc.), and other materials that deform when placed under a load and resiliently rebound (e.g., to their original shape, etc.) upon removing the load.

In some embodiments, the cushioning element may include stiffening features, or stiffeners. A stiffening feature, or stiffener, may be defined by the material (e.g., the elastomeric material, etc.) that defines the plurality of interconnected walls. Without limitation, a stiffening feature, or a stiffener, may comprise an enlarged junction between interconnected walls at a corner of a hollow column, or a cell, of the cushioning element. An enlarged junction may include one or more filleted (i.e., radiused) interior corners within the interior of a hollow column (i.e., a “filleted junction”) or any other suitable enlarged shape (e.g., a round cross-section, such as a circle, oval, ellipse, etc.; a polygonal cross-section, such as a diamond, square, etc.); etc.). Each dimension across each end of such an enlarged junction (e.g., in-line with the interconnected walls, diagonals, etc.) may exceed a thickness of each wall of the walls joined at the enlarged junction.

An arrangement of stiffening features across the cushioning element may at least partially define one or more cushioning characteristics of the cushioning element at different locations over a cushioning surface of the cushioning element. As an example, stiffening features may be arranged evenly across the cushioning element to impart the cushioning element with the same cushioning characteristics across an entirety of the cushioning surface or substantially across the cushioning surface (e.g., with the possible exception of edges of the cushioning element, etc.). As another example, locations of the cushioning surface that are intended to be relatively firm may include a firm arrangement of stiffening features (e.g., more stiffening features, larger stiffening features, etc.), while locations of the cushioning element that are intended to be relatively soft may include a soft arrangement of stiffening features (e.g., fewer stiffening features, smaller stiffening features, etc.).

A hollow column may include an enlarged junction (e.g., a filleted junction, etc.) at one corner. Alternatively, a hollow column may include enlarged junctions (e.g., filleted junctions, etc.) at a plurality of corners (e.g., opposite corners of the hollow column, etc.). As another alternative, each corner of a hollow column may include an enlarged junction (e.g., a filleted junction, etc.) (i.e., all of the corners of the hollow column may include enlarged junctions).

All of the hollow columns of the cushioning element may include at least one stiffening feature. Alternatively, only selected hollow columns of the cushioning element may include at least one stiffening feature. For example, hollow columns at corners of the cushioning element, hollow columns at outer edges of the cushioning element, hollow columns at locations of the cushioning element that are expected to receive the greatest load (e.g., midway between the head and foot of a mattress etc.) may include at least one stiffening feature.

Each hollow column of a cushioning element that includes at least one stiffening feature (e.g., one or more enlarged junctions, etc.) may be stiffened in the same manner (e.g., it may have the same number of enlarged junctions, etc.) as every other hollow column that includes at least one stiffening feature. As another option, the manner and extent to which each hollow column is stiffened (e.g., the type, number, and arrangement of stiffening features, such as enlarged junctions of the hollow column, etc.) may correspond to a location of the hollow column on the cushioning element. In some embodiments, the incorporation of stiffening features into a cushioning element with interconnected walls that define hollow columns may facilitate a reduction in the thickness of the cushioning element.

In some embodiments, the cushioning element may include voids in at least one wall that defines at least one hollow column. Such a void may comprise a feature that reduces material from the plurality of interconnected walls. In some embodiments, the void may comprise an opening in a wall of the plurality of interconnected walls. Such an opening may include a notch in an edge of the wall. Such an opening may include a window in the wall. In other embodiments, a void may comprise a recess, or thinned region (e.g., a dimple, etc.) in one or both surfaces of the wall.

Each void may have a size and shape that enables it to eliminate material from the wall, thereby reducing the weight of the wall and the weight and density of the cushioning element of which the wall is a part, without reducing the cushioning characteristics of the cushioning element. In some embodiments, the incorporation of voids into the walls of a cushioning element with interconnected walls that define hollow columns may facilitate a reduction in the thickness of the cushioning element without sacrificing the cushioning characteristics of the cushioning element.

An arrangement of voids in the walls across the cushioning element may at least partially define one or more cushioning characteristics of the cushioning element at different locations over a cushioning surface of the cushioning element. As an example, voids may be arranged evenly across the cushioning element to impart the cushioning element with the same cushioning characteristics across an entirety of the cushioning surface or substantially across the cushioning surface (e.g., with the possible exception of edges of the cushioning element, etc.). As another example, locations of the cushioning surface that are intended to be relatively firm may include a firm arrangement of voids (e.g., more voids, larger voids, different shaped voids, etc.), while locations of the cushioning element that are intended to be relatively soft may include a soft arrangement of voids (e.g., fewer voids, smaller voids, etc.).

A method for designing a cushioning element with a plurality of interconnected walls that define hollow columns may include determining one or more cushioning characteristics of the cushion and optimizing (e.g., minimizing, etc.) one or more of a thickness, weight, and density of the cushioning element to achieve the one or more cushioning characteristics. Such a method may include incorporating features into the cushioning element that optimize the weight and/or density of the cushioning element. Such a method may include designing features that enable the cushioning element to be thinner than it would be if the features were not included in the cushioning element design. As an example, such a method may include designing stiffening features into the walls of the cushioning element (e.g., enlarged junctions between walls of the plurality of interconnected walls, etc.). As another example, such a method may include designing the plurality of interconnected walls to include voids that reduce the amount of material required to define the plurality of interconnected walls while having little or no impact on the cushioning characteristics (e.g., compression, rebound, etc.) of the cushioning element vis-à-vis a cushioning element that lacks such voids (e.g., notches, windows, recessed areas, etc., in the interconnected walls of the cushioning element).

Other aspects of this disclosure, as well as features and advantages of various aspects of the disclosed subject matter, should be apparent to those of ordinary skill in the art through consideration of the ensuing description, the accompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a perspective view of a section of an existing cushioning element;

FIG. 2 is a perspective view of a section of an embodiment of a cushioning element that has been designed with an embodiment of stiffening features to provide the same or substantially the same cushioning characteristics as the section of the existing cushioning element shown in FIG. 1 , but with less thickness, weight, and/or density than the section of the existing cushioning element shown in FIG. 1 ;

FIG. 2 also shows an embodiment of voids in the walls that define a hollow column that may be used to provide a cushioning element with the same or substantially the same cushioning characteristics as the section cushioning element shown in FIG. 1 , but with less weight and/or thickness than the section of the existing cushioning element shown in FIG. 1 ;

FIG. 2A provides an enlarged view of an embodiment of void in a wall that defines part of a hollow column of the cushioning element of FIG. 2 ;

FIG. 3 is a perspective view of a section of another embodiment of a cushioning element that has been designed with other embodiments of voids in walls of the cushioning element and optional stiffening features to provide the same or substantially the same cushioning characteristics as the section cushioning element shown in FIG. 1 , but with less weight and/or thickness than the section of the existing cushioning element shown in FIG. 1 ;

FIGS. 4-7 are respectively front, left, top, and perspective views showing the results of a topology study on a 3 column by 3 column square section of a conventionally configured cushioning element, showing areas of interconnected walls of the cushioning element that should be kept and areas of the interconnected walls that may be removed without significantly affecting cushioning characteristics of the section of the cushioning element;

FIG. 8 is a graph showing the displacement of the section of the cushioning element shown in FIGS. 4-7 achieved under various loads in the topology study;

FIG. 9 is a graph comparing the cushioning characteristics of a cushioning element according to this disclosure to the cushioning characteristics of a thicker, heavier conventionally configured cushioning element;

FIGS. 10 and 11 respectively show the stresses on various locations of a 3 column by 3 column square section of a conventionally configured cushioning element that lacks stiffening features and voids in its walls and the stresses on various locations of a 3 column by 3 column square section of an embodiment of a cushioning element according to this disclosure (i.e., an optimized cushioning element);

FIGS. 12 and 13 respectively show the deflection of various locations of a 3 column by 3 column square section of a conventionally configured cushioning element that lacks stiffening features and voids in its walls and the deflection of various locations of a 3 column by 3 column square section of an embodiment of a cushioning element according to this disclosure (i.e., an optimized cushioning element);

FIGS. 14A-14E illustrate various embodiments of cushioning elements with interconnected walls that include voids that comprise recessed areas, or dimples; and

FIG. 15 is a perspective view showing the results of a topology study on an 8 column by 8 column square section of a conventionally configured cushioning element, showing areas of interconnected walls of the cushioning element that should be kept and areas of the interconnected walls that may be removed without significantly affecting cushioning characteristics of the section of the cushioning element.

DETAILED DESCRIPTION

FIG. 2 illustrates an embodiment of a cushioning element 10. The cushioning element 10 includes a plurality of walls 20. The walls 20 are connected to each other at junctions 22 and, thus, may be referred to as “interconnected walls.” The walls 20 are arranged in such a way as to define an array of cells or hollow columns 30. As illustrated, the walls 20 are arranged in a grid pattern and define hollow columns 30 with cross sections, taken transverse to the heights of the hollow columns 30, that are substantially square in shape (e.g., with rounded corners, etc.).

As illustrated by FIG. 2 , each junction 22 between interconnected walls 20 may be enlarged relative to the maximum thicknesses of the walls 20 that define the junction 22. More specifically, such a junction 22 may define a filleted (i.e., radiused) interior corner within the interior of a hollow column 30 and, thus, comprise a “filleted junction.” Each dimension across each end 23, 24 of such a junction 22 (e.g., in-line with the interconnected walls 20, diagonals, etc.) may exceed a thickness of each wall 22 that extends to the junction 22. Optionally, junctions 22 e may define exterior fillets (i.e., radiused protrusions) at exterior edges 10 e and/or corners 10 c of the cushioning element 10.

In addition, FIG. 2 shows an embodiment of a cushioning element 10 that includes voids 28 in the walls 20 that define portions of the hollow columns 30. More specifically, the voids 28 comprise notches (e.g., trapezoidal notches, rectangular notches, triangular notches, arched notches, etc.) that extend upwardly from a base 26 of a wall 22, toward a top edge 27 of the wall 20. The voids 28 may extend any length upwardly on the walls 20 from the base 26 and may be positioned on each wall 20 or on selected walls 20. FIG. 3A illustrates the shape and dimensions of a specific embodiment of a void 28.

The interconnected walls 20, including their junctions 22, may be formed from any of a variety of suitable cushioning materials that are readily compressible under a load and exhibit desired resiliency or rebound (e.g., elastic rebound, viscoelastic rebound, etc.). Without limitation, the interconnected walls 20 may be formed from an elastomeric material. The elastomeric material may comprise a gel and, accordingly, may be referred to as an “elastomeric gel.” Some non-limiting examples of elastomeric gels that may be used to form the interconnected walls 20 include extended block copolymers (e.g., plasticizer-extended block copolymers, such as oil-extended block copolymers and/or resin-extended block copolymers, etc.). More specifically, A-B-A triblock copolymers may be used. Examples of extended A-B-A block copolymers are disclosed by U.S. Pat. Nos. 6,413,458, 6,797,765, and 7,964,664, the entire disclosures of which are hereby incorporated herein.

When the cushioning element 10 is placed under a load, the hollow columns 30 may buckle, as described in U.S. Pat. Nos. 7,730,566 and 8,919,750, the entire disclosures of which are hereby incorporated herein, or bulge, as described in U.S. Patent Application Publication US 2019/0075884 A1, the entire disclosure of which is hereby incorporated herein.

Referring now to FIG. 3 , yet another embodiment of a cushioning element 10′ is shown. The cushioning element 10′ includes walls 20′. The walls 20′ are connected at junctions 22′. The walls 20′ define hollow columns 30′. Voids 28′ are defined in the walls 20′. The voids 28′ may include a lower void in a base 26′ of a wall 20′ and an upper void in a top edge 27′ of the wall 20′. More specifically, the voids 28′ have so-called “keyhole” shapes that extend to the base 26′ or the top edge 27′ of the wall 20′. In addition, selected junctions 22′ may be enlarged relative to the thicknesses of the walls 20′ that define such junctions 22′.

The interconnected walls 20′, including their junctions 22′, may be formed from any of a variety of suitable cushioning materials that are readily compressible under a load and exhibit desired resiliency or rebound (e.g., elastic rebound, viscoelastic rebound, etc.). Without limitation, the interconnected walls 20′ may be formed from an elastomeric material. The elastomeric material may comprise a gel and, accordingly, may be referred to as an “elastomeric gel.” Some non-limiting examples of elastomeric gels that may be used to form the interconnected walls 20′ include extended block copolymers (e.g., plasticizer-extended block copolymers, such as oil-extended block copolymers and/or resin-extended block copolymers, etc.). More specifically, A-B-A triblock copolymers may be used. Examples of extended A-B-A block copolymers are disclosed by U.S. Pat. Nos. 6,413,458, 6,797,765, and 7,964,664.

When the cushioning element 10′ is placed under a load, the hollow columns 30′ may buckle, as described in U.S. Pat. Nos. 7,730,566 and 8,919,750, or bulge, as described in U.S. Patent Application Publication US 2019/0075884 A1.

FIGS. 4-7 and 15 depict the results of a topology study that was conducted by fixing the location of a base 112 (i.e., the bottom edges 126, 226 of the walls 120, 220) of a section of an existing, conventionally configured cushioning element 110, 210 (see also FIG. 1 ) and applying a compressive force to a top 114 (i.e., the top edges 127, 227 of the walls 120, 220) of the section of the cushioning element 110, 210. The topology study was conducted with a Newton tester using ASTM F1566 compression test parameters. In FIGS. 4-7 , the topology study was conducted on a 3 column by 3 column square section of a 2 inch (5.1 cm) thick cushioning element 110. In FIG. 15 , the topology study was conducted on an 8 column by 8 column square, 2 inch (5.1 cm) thick section of a cushioning element 210. The walls 120, 220 of each section of the cushioning element 110, 210 were 0.12 inch (30 mm) thick and defined hollow columns 130, 230 with substantially square cross-sections taken transverse to the lengths of the hollow columns 130, 230. Junctions 122, 222 between interconnected walls 120, 220 were cylindrical in shape with diameters of 0.26 inch (67 mm). The center of each junction 122, 222 was spaced 1.2 inches (2.9 cm) from its adjacent junctions 122, 222 along the walls 120, 220 that define the junction 122, 222. Each section of the cushioning element 110, 210 was made from Purple's Hyper-Elastic Polymer 4.0 mix, which comprises an oil-extended A-B-A triblock copolymer.

FIG. 8 is a graph showing the displacement achieved under various loads in the topology study. The results of the topology studies depicted by FIGS. 4-7 revealed areas 125 s, 225 s of the walls 120, 220 of the cushion that provide the cushioning element 110, 210 with structural integrity, areas 125 u, 225 u of the walls 120, 220 that appear to be unnecessary for the cushioning element 110, 210 to function as intended (transparent areas, appearing as holes in the walls 120, 220), and areas 125 o, 225 o of the walls 110, 210 that may provide some structural integrity but may not be necessary for the cushioning element 110, 210 to function as intended.

For purposes of comparison to the existing, conventionally configured cushioning elements 110, 120, the topology study was computer-simulated on the embodiment of cushioning element 10 shown in FIGS. 2 and 2A, which has a thickness of 1¾ inch (4.4 cm), hollow columns 30 with 0.10 inch (2.5 mm) radiused inner corners, and voids 28 with the dimensions shown in FIG. 2A. FIG. 9 provides a comparison of the computer-simulated topology study to the above-described topology study (in reference to FIGS. 4-7 ). As illustrated by FIG. 9 , a thinner, lighter weight cushioning element according to this disclosure may provide the same cushioning characteristics as the conventionally configured cushioning element. These results were subsequently confirmed in an actual, physical topology study on prototypes of cushioning elements 10, 10′ using the same parameters as those used on the existing, conventionally configured cushioning elements 110 and 120.

FIG. 10 shows the stress on various locations of the section of the conventionally configured cushioning element 110 during the topology study. FIG. 11 shows an embodiment of a cushioning element 110′ that includes voids 128′ that comprise windows in selected walls 120′, which may be formed from the same materials as the walls 20, 20′ of other embodiments of cushioning elements 10, 10′ described herein. While the voids are depicted as comprising rectangular windows, other shapes of windows (e.g., windows with the shapes of other polygons, windows with rounded shapes, etc.) are also within the scope of this disclosure. FIG. 11 also shows computer modeling of the stress experienced by the cushioning element 110′ induced upon under the same conditions as those applied to the conventionally configured cushioning element 110 shown in FIG. 10 .

FIG. 12 shows the deflection of various locations of the section of the conventionally configured cushioning element 110 during the topology study. FIG. 13 shows a computer model of the deflection the same conditions induced in various locations of the section of the embodiment of the cushioning element 110′ that includes voids 128′ in selected walls 120′.

Turning now to FIGS. 14A-14E, embodiments of cushioning elements 310, 310′, 310″, 310′″ with voids 328, 328′, 328″, 328′″ that comprise recesses or dimples in surfaces of walls 320, 320′, 320″, 320′″ (which may be formed from the same materials as the walls 20, 20′ of other embodiments of cushioning elements 10, 10′ described herein) are depicted. FIGS. 14A and 14B depict such a void 328 at a base 326 or a top edge 327 of a wall 320 of a cushioning element 310, with FIG. 14B providing a cross-sectional view of the wall 320 that shows the void 328 as comprising recesses in opposite surfaces of the wall 320. FIG. 14C provides a cross-sectional representation of a wall 320′ of a cushioning element 310′ and a void 328′ in the wall 320′, with the void 328′ comprising a recess in only one surface of the wall 320′. FIG. 14D depicts an embodiment of a cushioning element 310″ with a wall 320″ that includes a void 328″ comprising at least one recess at an intermediate location along a height of the wall 320″, in one surface (see, e.g., FIG. 14C) or opposite surfaces (see, e.g., FIG. 14B) of the wall 320″. FIG. 14E shows an embodiment of a cushioning element 310′″ with a wall 320′″ that includes voids 328′″ comprising recesses at a base 326′″ and a top edge 327′″ of the wall 320′″, in one surface (see, e.g., FIG. 14C) or opposite surfaces (see, e.g., FIG. 14B) of the wall 320′″. Such voids 328, 328′, 328″, 328′″ may be used without or without stiffening features, such as the enlarged junctions 22 described previously herein in reference to FIG. 2 .

Cushioning elements that include combinations of different types of voids (e.g., openings, recesses, etc.) and/or voids at a plurality of different locations along the heights of the interconnected walls of the cushioning elements are within the scope of this disclosure. Such embodiments may lack stiffening elements or include stiffening elements.

With returned reference to FIG. 15 , the use of a topology study on an existing or conventionally configured cushioning element 210 may be used to identify locations of the walls 220 from which material may be omitted. Such information may be useful in determining the locations where voids (e.g., openings (e.g., notches, windows, etc.), dimples, etc.) may be provided in the walls while designing a similar, but less dense, lighter, and optionally thinner cushioning element that provides cushioning characteristics similar to those of the existing or conventionally configured cushioning element 210.

Although this disclosure provides many specifics, these should not be construed as limiting the scope of any of the claims that follow, but merely as providing illustrations of some embodiments of elements and features of the disclosed subject matter. Other embodiments of the disclosed subject matter, and of their elements and features, may be devised which do not depart from the spirit or scope of any of the claims. Features from different embodiments may be employed in combination. Accordingly, the scope of each claim is limited only by its plain language and the legal equivalents thereto. 

What is claimed:
 1. A cushioning element, comprising: a plurality of interconnected walls formed from an elastomeric material, defining a plurality of hollow columns, with each hollow column of the plurality of hollow columns including: at least one stiffening feature; and at least one void in at least one wall of the plurality of interconnected walls.
 2. The cushioning element of claim 1, wherein the at least one stiffening feature comprises an enlarged junction defining a corner of each hollow column at a location where walls of the plurality of interconnected walls join each other, each dimension across each end of the enlarged junction exceeding a thickness of each wall of the walls joined at the enlarged junction.
 3. The cushioning element of claim 2, wherein each corner of each hollow column comprises the enlarged junction.
 4. The cushioning element of claim 1, wherein the at least one stiffening feature is defined by the elastomeric material.
 5. The cushioning element of claim 1, wherein the at least one void comprises an opening in at least one wall of the plurality of interconnected walls.
 6. The cushioning element of claim 5, wherein the opening comprises a notch in an edge of the at least one wall.
 7. The cushioning element of claim 5, wherein the opening comprises a window in the at least one wall.
 8. The cushioning element of claim 1, wherein the elastomeric material comprises a gel.
 9. The cushioning element of claim 8, wherein the gel comprises a block copolymer and a plasticizer.
 10. The cushioning element of claim 9, wherein the block copolymer comprises a triblock copolymer.
 11. The cushioning element of claim 10, wherein the triblock copolymer comprises an A-B-A triblock copolymer.
 12. The cushioning element of claim 1, wherein the plurality of hollow columns buckle when at least a portion of the cushioning element is placed under a load.
 13. A cushioning element, comprising: a plurality of interconnected walls formed from an elastomeric material, defining a plurality of hollow columns, with each hollow column of the plurality of hollow columns including at least one void in a wall of the plurality of interconnected walls.
 14. The cushioning element of claim 13, wherein the at least one void comprises at least one notch formed in an edge of the wall.
 15. The cushioning element of claim 14, wherein the at least one notch is formed in a bottom edge of the wall.
 16. The cushioning element of claim 13, wherein the at least one void comprises a window formed in the wall.
 17. The cushioning element of claim 13, wherein the at least one void is formed in a plurality of walls of the plurality of interconnected walls defining each hollow column.
 18. The cushioning element of claim 17, comprising at least one void in each wall defining each hollow column.
 19. The cushioning element of claim 13, further comprising: at least one stiffening feature.
 20. The cushioning element of claim 19, wherein the at least one stiffening feature comprises an enlarged junction at a corner of each hollow column of the plurality of hollow columns, each dimension across each end of the enlarged junction exceeding a thickness of each wall of the plurality of interconnected walls joined at the enlarged junction.
 21. The cushioning element of claim 19, wherein the at least one stiffening feature comprises an enlarged junction at a plurality of corners of each hollow column of the plurality of hollow columns, each dimension across each end of the enlarged junction exceeding a thickness of each wall of the plurality of interconnected walls joined at the enlarged junction.
 22. The cushioning element of claim 19, wherein the at least one stiffening feature comprises an enlarged junction at each corner of each hollow column of the plurality of hollow columns, each dimension across each end of the enlarged junction exceeding a thickness of each wall of the plurality of interconnected walls joined at the enlarged junction.
 23. The cushioning element of claim 13, wherein the plurality of hollow columns buckle when at least a portion of the cushioning element is placed under a load.
 24. A method for designing a cushioning element with a plurality of interconnected walls defining an array of hollow columns, comprising: stiffening at least portions of the plurality of interconnected walls to enable minimization of a thickness of the cushioning element to provide predetermined compression and rebound characteristics; and/or designing the plurality of interconnected walls to include voids.
 25. The method of claim 24, wherein stiffening at least portions of the plurality of interconnected walls comprises designing enlarged junctions at corners of the hollow columns to stiffen the corners, each dimension across each end of each enlarged junction exceeding a thickness of each wall of the plurality of interconnected walls joined at the enlarged junction.
 26. The method of claim 24, wherein designing the plurality of interconnected walls to include voids comprises designing the plurality of interconnected walls to include notches in edges of the plurality of interconnected walls and/or windows in the plurality of interconnected walls.
 27. The method of claim 24, comprising stiffening at least portions of the plurality of interconnected walls and designing the plurality of interconnected walls to include voids.
 28. The method of claim 24, further comprising: designing the array of hollow columns to buckle when placed under a load. 